Our understanding of the sense of taste is largely based on research designed and interpreted in terms of the traditional four tastes: sweet, sour, salty, and bitter, and now a few more. This concept of basic tastes has no rational definition to test, and thus it has not been tested. As a demonstration, a preliminary attempt to test one common but arbitrary psychophysical definition of basic tastes is included in this article; that the basic tastes are unique in being able (...) to account for other tastes. This definition was falsified in that other stimuli do about as well as the basic words and stimuli. To the extent that this finding might show analogies with other studies of receptor, neural, and psychophysical phenomena, the validity of the century-long literature of the science of taste based on a few is called into question. The possible origins, meaning, and influence of this concept are discussed. Tests of the model with control studies are suggested in all areas of taste related to basic tastes. As a stronger alternative to the basic tradition, the advantages of the across-fiber pattern model are discussed; it is based on a rational data-based hypothesis, and has survived attempts at falsification. Such has found broad acceptance in many neural systems. (shrink)

The T/t locus was a major focus of study by mouse geneticists during the 20th century. In the 70s, as the study of cell surface antigens controlling transplantation antigens was taking off, several laboratories hypothesized that alleles of this locus would control cell surface antigens important for embryonic development. One such antigen, the embryonal carcinoma F9 antigen was said to be an example. Other antigens were described on sperm and embryos that were said to be controlled by alleles at the (...) T/t complex. These findings were later found to be false. The history of the findings and their refutation is described. (shrink)

Recent molecular studies of mammalian sexual determination have been focused on gene expression in the gonadal ridge at the time of appearance of sexual dimorphism: the critical time defined by the ‘Jost principle’. Three lines of evidence suggest that, instead, sex determination may start shortly after conception: (1) the XY preimplantation embryo usually develops more rapidly than the XX preimplantation embryo (this phenotype has been linked to the Y chromosome and will be termed ‘Growth factor Y’); (2) the gene for (...) testis determination, SRY/Sry, and the closely linked genes ZFY/Zfy and Smcy, are transcribed in the preimplantation embryo; and (3) male and female preimplantation embryos are antigenically distinguishable, indicating sex differences in gene expression. The data to support these assertions are reviewed. Possible relationships of these three phenomena to each other and to sex differentiation are discussed. Similarities in mechanisms of sexual determination between marsupial and eutherian mammals are hypothesized. Problems with interpreting male sexual differentiation as being solely due to testosterone and Müllerian inhibiting substance (MIS) are discussed. (shrink)

There has always been great interest in animal models of human genetic disease, and mice provide the largest number of examples. A mutation in the homologous gene in mice does not always lead to the same phenotype as is found in man, however. Recent studies made it apparent that one mutation can have markedly different phenotypes when placed on different genetic backgrounds. This variation is due to different alleles at modifying loci in various inbred strains. Thus, if one wishes to (...) obtain the optimal mouse model for a human disease, one needs to choose the correct genetic background as well as the correct mutation. (shrink)

The target article described the ubiquitous and often undefined idea of as the basis for sensory coding in taste, and its attendant problems. The commentaries cover the full range of reaction to this argument, from full support, to qualification of the level of analysis to which apply and the nature of empirical support, to full denial of either the characterization of the literature or that such characterization reveals any problem. Many commentators, and I, go on to propose other types and (...) sources for taste analysis, which I relate to the. (shrink)